Results 1 to 3 of 3

Math Help - Are equilateral triangles isosceles?

  1. #1
    Member mathemagister's Avatar
    Joined
    Feb 2010
    Posts
    191

    Are equilateral triangles isosceles?

    I have noticed that there is no real "convention" about the question of whether isosceles are defined to have 2 equally long sides, or at least 2 equally long sides. Several websites I went to have contradicted each other. Any ideas?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Yes,

    if you start with a horizontal line,
    then raise the midpoint above it to form an isosceles triangle of any height,
    the angles at both ends of the base go from zero to 90 degrees,
    as the triangle goes from a horizontal line to a vertical line.
    Somewhere between those extremes, the isosceles triangle is also equilateral.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member mathemagister's Avatar
    Joined
    Feb 2010
    Posts
    191
    Quote Originally Posted by Archie Meade View Post
    Yes,

    if you start with a horizontal line,
    then raise the midpoint above it to form an isosceles triangle of any height,
    the angles at both ends of the base go from zero to 90 degrees,
    as the triangle goes from a horizontal line to a vertical line.
    Somewhere between those extremes, the isosceles triangle is also equilateral.
    Thanks, I wasn't really sure because I saw the "exactly 2 sides of equal length" definition on a relatively reliable website, but I'll go with you and what Wolfram says.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: March 24th 2011, 07:08 AM
  2. Equilateral Triangles.
    Posted in the Geometry Forum
    Replies: 4
    Last Post: January 6th 2011, 06:48 AM
  3. Equilateral triangles
    Posted in the Geometry Forum
    Replies: 2
    Last Post: January 18th 2010, 01:52 PM
  4. equilateral triangles
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 21st 2009, 03:03 AM
  5. Isosceles Triangles
    Posted in the Advanced Math Topics Forum
    Replies: 1
    Last Post: October 5th 2006, 10:38 AM

Search Tags


/mathhelpforum @mathhelpforum